Siemens scanner used by the structural intervention team in the cardiology department at Guy's and St Thomas'.
Image courtesy of Siemens
Structural intervention is a general term that is used to describe minimally invasive techniques for treating various heart conditions. We have one of the largest structural interventional cardiology departments within the United Kingdom and an international reputation in this field. We are considered to be one of the leading centres in the world for transcatheter valve therapies and performed the world’s first three transcatheter mitral valve replacements in 2014.
Structural intervention procedures are able to treat patients with:
- conditions of the aortic, mitral or tricuspid valve which are deemed to be too high-risk for conventional major surgery (percutaneous valve interventions).
- holes in their hearts (atrial and ventricular septal defects) that need to be closed (percutaneous ASD/VSD closure).
- leaking around prosthetic valves (paravalvular leak closure)
- atrial fibrillation and an inability to take blood thinning agents (left atrial appendage occlusion).
- heart failure (parachute device implantation).
At Guy’s and St Thomas’ we have a comprehensive service for evaluating patients who may be suitable for innovative procedures to treat the following conditions:
Aortic stenosis (transcatheter aortic valve implantation)
Aortic stenosis is a condition where the aortic valves progressively calcifies to cause obstruction to blood flow out of the heart and resulting symptoms of chest pain, breathlessness or dizziness.
In the last 10 years, new technologies have emerged to allow replacement of the aortic valve using a minimally invasive approach that is particularly suited for patients who are judged to be too high risk for major cardiac surgery. The procedure may also be suitable for patients with degeneration of a previous surgically implanted valve.
Guy's and St Thomas' Hospital were one of the early adopters of this technology and have one of the largest experiences in the UK. We have performed over 600 procedures to date and now undertake approximately 180 of these procedures per annum.
Mitral regurgitation (transcatheter mitral valve replacement)
Mitral regurgitation is a condition where the mitral valve becomes incompetent and leaks. Although the gold standard treatment remains conventional surgical mitral valve repair or replacement, this procedure is considered to be too risky in a proportion of patients.
Guy's and St Thomas' Hospitals are one of only a few centres in the world with experience in implanting new mitral valves using a minimally invasive, transcatheter approach. We implanted the world's first three minimally invasive transcatheter mitral valves minimally invasive transcatheter mitral valves and have since adopted newer technologies and an established service for evaluating potential patients for these new procedures.
Patent foramen ovalve (patent foramen ovale closure)
During fetal life, a communication exists between the two inlet chambers of the heart that closes in three quarters of people shortly after birth. In some people, this remains open and can increase the risk of certain types of stroke and decompression illness when diving. When this is thought to be important, the hole can be closed with a small procedure to place a metal “plug” in the defect to reduce this risk. As this is a complex decision, this is managed through a series of multi-disciplinary meetings both here and in our referring centres.
St Thomas’ Hospital is one of only a limited number of commissioned services within London carrying out in excess of thirty procedures a year and provides a robust specialist clinic to assess these patients. In addition to dealing with stroke patients, Dr Brian Clapp has a wide experience of diving medicine and acts as an accredited specialist for the Health and Safety Executive.
Paravalvular leaks (paravalvular occlusion service)
Patients who have undergone valve replacement surgery may develop leaks around the newly implanted valve to cause symptoms of shortness of breath, heart failure or anaemia. It is now possible to close these holes with little plugs using a minimally invasive approach.
At Guy's and St Thomas' Hospital we have a dedicated service that is able to evaluate patients for these procedures using detailed clinical assessment and advanced cardiac imaging using 3D echocardiography and computed tomography.
Atrial fibrillation and inability to take blood thinning agents
(left atrial appendage occlusion)
Patients with an irregular heart rhythm, known as atrial fibrillation, are at increased risk of suffering from strokes, and this often needs to be reduced with treatment. In most patients, this is achieved with blood thinning drugs such as warfarin or novel oral anti-coagulants, such as apixiban. For the minority of patients, these agents lead to dangerous bleeding and have to be stopped, and in those cases, we are able to reduce the risk of strokes by implanting a small device into an outpouching of the left inlet chamber called the left atrial appendage. This is a small operation that is carried out from an incision at the top of the leg.
St Thomas’ Hospital is one of only ten centres nationally commissioned for this procedure, and we offer a robust service beginning with specialist clinics, supported by very high quality imaging and a dedicated team of nurse case managers. The procedures are carried out jointly by the two leads for the service and we have an excellent success rate with relatively few complications.
Heart failure (parachute device implantation service)
Parachute device used to treat some patients with heart failure.Patients with heart failure are usually treated with medical therapy and special pacemakers. However, some remain significantly debilitated by their symptoms despite these measures – those who have developed abnormal stretching of their heart muscle may benefit from implantation of a minimally invasive device to improve their symptoms. This device is known as the parachute device, and St Thomas' Hospital are the only hospital in the UK with a dedicated service to evaluate patients for this procedure.
Complex acquired and congenital lesions (e.g. aortic
and ventricular pseudoaneurysms and coronary fistulas)
Various complex congenital and acquired lesions are treated by our structural intervention team.Various complex congenital and acquired lesions are dealt with via multidisciplinary discussion and advanced techniques utilising novel devices and hybrid approaches to therapy.
Patients who are potentially suitable for having these procedures undergo a detailed assessment by a multidisciplinary team, a clinical assessment and advanced cardiac imaging.